Grantee Research Project Results
Portable Desalination Using Ocean and Solar Energy
EPA Grant Number: SU839910Title: Portable Desalination Using Ocean and Solar Energy
Investigators: Zuo, Lei
Current Investigators: Zuo, Lei , Mi, Jia , Capper, Joseph , Chen, Shuo , Jones, Erin , Lane, Jimmy , Vencill, Ethan , O'Donnel, Dana
Institution: Virginia Tech
EPA Project Officer: Page, Angela
Phase: I
Project Period: October 1, 2019 through September 30, 2020 (Extended to August 31, 2021)
Project Amount: $25,000
RFA: P3 Awards: A National Student Design Competition Focusing on People, Prosperity and the Planet (2019) RFA Text | Recipients Lists
Research Category: P3 Awards , P3 Challenge Area - Safe and Sustainable Water Resources
Description:
The objective of project is to develop a low-cost self-sustainable portable desalination system using wave and solar renewable energy, scalable for personal usage or for the usage of small communities. Water is one of nature's most important resources to mankind. It covers 71% of the earth's surface. However, 97% of the water is salt water and only 1% of the world's water supply is available for our survival. The 21st century has been named the "century of water shortage", and its first and second decades called "water crisis decades". Over 53% people live within 50 miles of coastal line in USA, however, many coastal areas, such as California, are short of fresh water. There are more than 50,000 islands in the world, which accounts about 10% of global population. Lack of fresh water has become one of the most important factors for the global economic and social development. Desalination plants are built to supply fresh water, however, the plants need huge energy and produce large greenhouse gases (GHG) emissions. In addition, such kind of dilemma is not just occurring on islands or coastal lines, inland salt lakes also suffer fresh water and energy shortage. The global volume of inland saline water is estimated to be 81% of the freshwater lakes. Hence, saline water desalination power by renewable energy should be developed and promoted.
Approach:
The proposed portable desalination system is composed of a three-body wave energy converter (WEC) powered two hydraulic pumps, a solar heating module on the WEC bodies, and a thermal membrane desalination (MD) module. Such a system can be deployed in the ocean or salty lake to produce freshwater from the wave and solar energy. The two floating bodies of Salter's Duck shape in the WEC will be driven by the waves and rotate around two hinges on the main body of the WEC. Mechanical motion rectifier (MMR), a novel power takeoff (PTO) system, is applied to convert the bidirectional rotation of the hinges into unidirectional rotation, and then pump the saline water effeciently. Attached on the surface of main body and floating bodies are solar panels, which can heat the salt water pumped by the WEC. Inside the main body is a thermal membrane distillation (MD) module, which products fresh water from saline water. In the MD module, a hydrophobic membrane allows the water vapor phase in hot feed flow side to pass through the membrane's pores of 0.1-0.5 um and condense on the cooler side. The driving force of the process is given by a partial vapor pressure difference triggered by a temperature difference of hot feed flow on one side and a cooled permeate flow on the other side.
Expected Results:
In phase I of this project, the team will develop and demonstrate a functional desalination prototype powered with wave and solar hybrid energy for the typical basic daily fresh water consumption of one person. The wave powered pump system based on Salter's Duck and shape design of the main body will be tested in wave tank to evaluate the best shape design and parameters matching. We can scientifically evaluate its mechanical and hydrodynamic characteristics, especially the mechanical stress and the energy harvesting capability. Meanwhile, the solar thermal based water heating system will be designed and tested in different light conditions. All the data will be recorded and further analyzed for the purpose of adjustment and optimization. The feasibility will be demonstrated through in-field test. If successful, this technology can solve both water and energy problems for communities in coastal zones, isolated islands and inland salt lakes, provides safe and low-cost fresh water with renewable energy, and reduce pollution to our planet.
Publications and Presentations:
Publications have been submitted on this project: View all 3 publications for this projectSupplemental Keywords:
Saline Water Desalination, Ocean Wave Energy Converter, Solar Heating, Renewable EnergyProgress and Final Reports:
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.